1. Field of the Invention
The present invention relates to a system for controlling the access to a store of information stored in divisable form in machine readable media using a unique code and particularly, but not exclusively, is suitable for controlling the length of time a computer program is used. The system can also be used to control the length of time a piece of hardware, such as a VCR or computer is used.
2. Description of the Related Art
Computer programs require considerable effort to create and debugg, particularly those for use in engineering projects and the like. Such programs are invariably specialised and are expensive to create and to buy. Many potential users are deterred by the price because they may require to use the program infrequently and find it difficult to justify the relatively high purchase cost. This means that many projects are limited in the number of complexity of data processing power and handling which can be handled by such programs. Another factor deterring purchase is that programs are being continuously improved so that the risk of having an obsolete expensive program is of considerable concern.
An object of the present invention is to provide a system which obviates or mitigates the aforesaid disadvantages.